One quarter of patients with atrial fibrillation who were at a low risk for stroke were prescribed oral anticoagulants, contrary to guidelines. The results appeared online April 13 in JAMA Internal Medicine.

Jonathan C. Hsu, MD, MAS, of the University of California, San Diego, and colleagues analyzed data from the National Cardiovascular Data Registry’s PINNACLE registry between 2008 and 2012 to identify patients diagnosed with atrial fibrillation. They focused on patients who were under the age of 60 and healthy, with no structural heart disease or a history of thromboembolism.

Oral anticoagulants such as warfarin or newer approved agents reduce the risk of stroke in some patients with atrial fibrillation but they also increase the risk of bleeding. Guidelines recommend against using oral anticoagulants in younger and healthy patients because the bleeding risk may outweigh the preventive benefit.  

They looked at two different subgroups: those with a CHADS₂ (congestive heart failure, hypertension, age 75 years or less, diabetes mellitus and prior stroke, transient ischemic attack or thromboembolism) score of 0 and those with a CHA₂DS-VASc (congestive heart failure, hypertension, age 64 to 75 years, diabetes mellitus, vascular disease, female sex and prior stroke, transient ischemic attack or thromboembolism at 75 years old or older) score of 0. Physicians prescribed oral anticoagulants to 23.3 percent of patients with a CHADS₂ score of 0 and 26.6 percent of those with a CHA₂DS-VASc score of 0.

After adjustments, clinical predictors of oral anticoagulation prescription on atrial fibrillation patients with a CHADS₂ score of 0 included older age, male sex, a higher body mass index and Medicare insurance rather than private insurance. Predictors with a CHA₂DS-VASc score of 0 were a higher body mass index, Medicare insurance rather than private insurance and no insurance compared with private insurance. In both groups, patients treated in the South were less likely to receive oral anticoagulants than patients in the Northeast.

The authors proposed that physicians prescribing oral anticoagulants may not be fully informed about the potential bleeding risk or that this specific patient population is at a low risk of stroke. In a press release, Hsu called the results “a wakeup call that we need to do better for our patients.”

Using a registry has its shortcomings, though. They pointed out that they could not determine if these patients received oral anticoagulants as a treatment unrelated to atrial fibrillation such as a previous pulmonary embolism or deep vein thrombosis or as a temporary therapy after a catheter ablation procedure.